Screen shot of the 2D drawing I created in AutoCAD using photographs provided by Jay Barnaby and Scott Marion.

This drawing depicts a set of U30C or C30-7 sideframes designed to fit the Atlas U30C/U33C/C30-7 drive. The prototype uses trucks with a wider spacing between axles 2 and 3 and a narrower spacing between axles 1 and 2, as in the truck at the top. This arrangement is mirrored on the U30C and C30-7, with the greater spacing being between axles 4 and 5 and the lesser spacing between axles 5 and 6.

The axle spacing on the model's rear truck is identical to the front truck. That is, the distance between axles 1 and 2 equals the distance between axles 4 and 5. Likewise, the distance between axles 2 and 3 equals the distance between axles 5 and 6.

To accommodate the model, the sideframe depicted in the bottom of the image has been modified to match the axle spacing but have the general arrangement of the prototype.

Since the C36-7 has front and rear trucks facing the same direction, using two each of the sideframes at the top of the image results in the correct arrangement on the model. By substituting a second front truck for the rear truck on the Atlas model, it is possible to use the same set of sideframes as the C36-7 for the U30C and C30-7 models.